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March 8, 2022
Blow Molding Machine
Blow moulding, also known as blow moulding, is a rapidly developing plastic processing method. The tubular plastic parison obtained by extrusion or injection molding of thermoplastic resin is placed in a split mold while it is hot (or heated to a softened state), and compressed air is introduced into the parison immediately after closing the mold to blow the plastic parison. It expands and sticks closely to the inner wall of the mold, and after cooling and demoulding, various hollow products are obtained. The manufacturing process of blown film is very similar in principle to blow molding of hollow products, but it does not use a mold. From the perspective of plastic processing technology classification, the molding process of blown film is usually included in extrusion. The blow molding process began to be used to produce low density polyethylene vials during World War II. In the late 1950s, with the birth of high-density polyethylene and the development of blow molding machines, blow molding technology was widely used. The volume of hollow containers can reach thousands of liters, and some production has adopted computer control. Plastics suitable for blow molding include polyethylene, polyvinyl chloride, polypropylene, polyester, etc., and the obtained hollow containers are widely used as industrial packaging containers. According to the method of making the parison, blow molding can be divided into extrusion blow molding and injection blow molding. The newly developed ones include multi-layer blow molding and stretch blow molding.
The energy saving of the blow molding machine can be divided into two parts: one is the power part and the other is the heating part. Energy saving in the power part: most of them use frequency converters. The energy saving method is to save the excess energy consumption of the motor. For example, the actual power of the motor is 50Hz, and you actually only need 30Hz in production. Wasted, the frequency converter is to change the power output of the motor to achieve the effect of energy saving. Energy saving in the heating part: Most of the energy saving in the heating part is the use of electromagnetic heaters to save energy, and the energy saving rate is about 30%-70% of the old-fashioned resistance coil. 1. Compared with resistance heating, the electromagnetic heater has an additional layer of insulation layer, which increases the utilization rate of heat energy.
2. Compared with resistance heating, the electromagnetic heater directly acts on the heating of the material tube, which reduces the heat loss of heat transfer.
3. Compared with resistance heating, the heating speed of electromagnetic heaters is more than a quarter faster, which reduces the heating time.
4. Compared with resistance heating, the heating speed of the electromagnetic heater is fast, the production efficiency is improved, and the motor is in a saturated state, which reduces the power loss caused by high power and low demand.
The above four points are the reasons why Feiru electromagnetic heater can save energy as high as 30%-70% on the blow molding machine.
Blow molding machines can be divided into three categories: extrusion blow molding machines, injection blow molding machines and special structure blow molding machines. Stretch blow molding machines can fall into each of the above categories. Extrusion blow molding machine is a combination of extruder, blow molding machine and mold clamping mechanism. It consists of extruder and parison die, inflation device, mold clamping mechanism, parison thickness control system and transmission mechanism. The parison die is one of the important parts that determines the quality of blow molding products, and there are usually side feed die and central feed die. When large-scale products are blow-molded, the accumulator-type parison die is often used. The minimum volume of the storage tank is 1kg and the maximum can reach 240kg. The parison thickness control device is used to control the parison wall thickness, and the control points are up to 128 points, generally 20 to 30 points. The extrusion blow molding machine can produce hollow products with a volume ranging from 2.5ml to 104l. Injection blow molding machine is a combination of injection molding machine and blow molding mechanism, including plasticizing mechanism, hydraulic system, control electrical appliances and other mechanical parts. Common types are three-station injection blow molding machines and four-station injection blow molding machines. The three-station machine has three stations for preform, inflation and demoulding, and each station is separated by 120°. The four-station machine has one more preforming station, and each station is separated by 90°. In addition, there are dual-station injection blow molding machines with 180° separation between the stations. The plastic containers produced by the injection blow molding machine are accurate in size and do not require secondary processing, but the mold cost is high. The special structure blow molding machine is a blow molding machine that blows hollow bodies with special shapes and uses from sheets, molten materials and cold blanks as parisons. Due to the different shapes and requirements of the products produced, the structure of the blow molding machine is also different.
1. The central shaft of the screw and the cylinder are made of 38CrMoAlA chromium, molybdenum and aluminum alloy treated with nitrogen, which have the advantages of high thickness, corrosion resistance and wear resistance. 2. The die head is chrome-plated, and the screw mandrel structure makes the discharge more even and smooth, and the blown film is better completed. The complex structure of the film blowing machine makes the output gas more uniform. The lifting unit adopts a square frame platform structure, and the height of the lifting frame can be automatically adjusted according to different technical requirements. 3. The unloading equipment adopts peeling rotating equipment and center rotating equipment, and adopts torque motor to adjust the smoothness of the film, which is easy to operate.